Volty is spot on, there is only one line entering the bend which creates a follow the leader syndrome. I have spoken at length to three different track men, all of them are telling me the same thing - the straights are too long for the bends and the entry is too narrow.
No amount of messing about with the surface will cure the basic problem of the shape, Even the Doc couldn't cure this patient (excuse the pun). In any case anyone can have the same shale mix that he uses - it's a blend of product from two sources purchased from a quarry group well known to patrons of BP.
There is obviously a reason why it wasn't changed in the winter, DH had certainly indicated to me that it would be and Glyn certainly thought so. The reason I'm led to believe is finincial, drains would have to be moved in order to take in the kerb. I don't know the cost of this but a couple of people, including someone who has done similar work elsewhere, have mentioned as low as £6K and up to £10K, so take your pick.
That's obviously not pocket money but not a fortune either, and I reckon more will be lost in gate receipts by not doing the work in the long term.
I'm not a knocker of DH or the management at BP, I happen to get on well with just about everyone involved. But short term finincial pain is preferable to the alternative. No business can supply a product or service that it's customers are not happy with and have a viable future. Eventually the customer base will diminish to such an extent that the enterprise is no longer viable.